The present invention relates generally to a method of producing a low-fat meat product. More particularly, the invention relates to a method for the production of naturally defatted and decholesteroled cooked or uncooked meat to provide food products with extremely low-fat and low saturated fat, while also providing significantly reduced cholesterol and calories. The product exhibits enhanced taste and is free from chewiness and toughness normally associated with low-fat meats.
In recent years, a great deal of attention has been focused on the relationship between dietary total fat, saturated fat, and cholesterol intake on the one hand and the incidence of diseases of the blood vessels, such as coronary heart disease and arteriosclerosis, on the other hand. As a consequence of these studies and concerns, medical professionals have been advising the reduction of human consumption of animal fat. This suggestion has resulted in a decline of meat consumption, particularly of red meat which is known to contain high levels of saturated fat and cholesterol. The declined consumption of meat has adversely affected the meat industry resulting in economic losses. On the other hand, the consumption of poultry and fish products have been increasing because they contain less total fat, as well as less saturated fat and cholesterol than red meat.
The red meat industry has reacted to such consumption decline by recently introducing a low-fat hamburger (10-13% fat) using more expensive leaner cuts and adding carrageenan and other moisture binders to sustain juiciness. Other products recently introduced include a 4% fat lean ground beef product containing hydrolyzed oat fiber. Nevertheless, the fat and saturated fat levels in such meats are still quite high with regard to the currently recommended healthy diet (the Surgeon General's recommendation is no more than 30% of calories from fat). Individuals with restricted diet requirements, as well as health-conscious consumers, can obtain only modest reductions of total fat and cholesterol intake. Furthermore, only expensive lean meats can be utilized, which in return make such products cost prohibitive for most consumers and further limit the consumption potential.
Numerous attempts have been undertaken to reduce the fat in red meat. Unfortunately, all approaches have revolved around reducing the fat only to relatively high levels of
approximately 4-10% or greater. These fat levels, saturated fat and cholesterol are not reduced to acceptable levels for health conscious consumers and individuals with restricted diet requirements.
Several processes have been developed to treat meats from various animal sources to reduce their fat content. These processes typically have concerned one or more of the following three approaches. First, the removal of some fat from meat has been accomplished by mechanical means such as a crusher, a press or a cutting tool; and these means are exemplified by U.S. Pat. Nos. 4,776,063, 3,780,191, 3,748,148, 3,685,095, 3,078,287, 3,270,041 and 4,948,607; Japanese Patent Publications Nos. 62265396 (871118) and 61158763 (860718); French Pat. No. 2,187,229; and British Pat. No. 1179418. Second, treatments including heat, light, and reaction of gases with meats are described in Japanese Patent Publication Nos. 62278967 (871203), 61058533 (860325), 59173070 (840929), 59084993 (840516) and 58187496 (831101); Soviet Union Publication Nos. 1153874 (850507), 627810 (780821), 502011 (76082) and 1318420 (690331); and U.S. Pat. Nos. 3,687,819, 3,780,075 and 3,532,593. Third, chemical treatments with water or strong chemical reagents are described in Soviet Union Publication Nos. 1329737 (870815), 1063824 (831230) and 1017684 (830515); German Patent Publication Nos. 200156 (830323), 3169440 (850425) and 2119608 (710422); Japanese Patent Publication Nos. 56018537 (810221), 55156569 (801205), 54003099 (790111) and 52040473 (770329); and U.S. Pat. Nos. 3,794,743 and 3,532,593.
Some additives, such as food gels, have also been utilized to reduce the fat level in meat products (U.S. Pat. No. 4,844,922), or a Konjac Mannan gel (U.S. Pat. No. 4,876,103) and milk proteins (U.S. Pat. No. 4,504,515). U.S. Pat. No. 4,847,099 is directed to an apparatus for cooking meat in home and commercial kitchens by suspending the meat in a partially closed container above boiling water wherein the meat is exposed to steam.
A different method for reducing the cholesterol and saturated fat content of red meat and fowl is described in U.S. Pat. No. 4,980,185. This patent is directed to use of a heated unsaturated oil to solubilize the saturated fat and cholesterol of fragmented meat, then an aqueous fluid is used to separate and remove the extracting oil from the oil-processed meat. According to this patent, the fat content was reduced from 20.8% to 18.5% (only an 11% reduction) and cholesterol was reduced from 115mg to 80mg of cholesterol per 100 g beef (only a 30% reduction). Both reductions are relatively insignificant and do not offer much advantage over merely trimming the extra fat manually. Other drawbacks are that the method produces pre-cooked meats, the product must be declared as imitation meats because they contain vegetable oil and the caloric value will be as high as regular high fat ground beef.
Another method for lowering the fat and cholesterol levels in meat is set forth in U.S. Pat. No. 4,778,682. In this patent, a thin layer of meat is exposed to ultraviolet light. The meat is then comminuted in a chilled bowl with the addition of iced water, edible acid, salt, and food phosphates until a quantity of fat and cholesterol separate from the meat emulsion and adhere to the inner surface of the cold bowl. The limitation of this invention is the impracticality of having to expose thin layers of meat to ultraviolet light for up to twelve hours. In addition, health hazards might be created by virtue of forming free radicals by exposing the meat to radiation.
U.S. Pat. No. 4,680,183 describes another example of using heat treatment in the production of low-fat meat from cheaper cuts of meat. Furthermore, the process of the removal of sterols and/or lipid components from lipid containing food products using sub or super-critical fluids (e.g., carbon dioxide) is explained in U.S. Pat. No. 5,026,565. This patent describes food initially processed to produce an intermediate moisture product with substantially all of the free water, but not all of the bound water is removed to produce a moisture level between 30-55%. Such an intermediate product is treated with super-critical carbon dioxide to remove the lipid. The product can be treated with water and fat to provide a reconstituted meat product. Such chemical treatments are, however, considered undesirable for food products. Recent report indicate there are detrimental effects of sub or super-critical fluids on blood cholesterol. At the least, these products would be perceived by consumers as being artificial products.
Canadian Patent No. 463,736 is directed to a process for defatting pork skins for gelatin manufacturing. The process involves coarse and fine grinding of pork skins which are subjected to dilution and flotation in water to remove the fat from animal tissues. These steps are followed by agitation in a moving current of air to produce a suitable base for gelatin manufacturing.
In another approach U.S. Pat. No. 3,780,191 describes a process for reducing the fat content of frozen meat by comminuting a frozen portion of meat and obtaining discrete frozen meat particles and discrete frozen fat particles. Upon the addition of water, the particles are mechanically separated into reduced fat meat and fat particles. Such a process could reduce the visible fat in frozen meat into a level achievable by manual trimming of fats, but it does not remove the difficult to eliminate, intramuscular fat, or the fat-laden connective tissues and the cholesterol which is located in the cell membranes.
Despite all these innovations, the currently known procedures collectively remain ineffective for the purpose of substantially reducing total fat and cholesterol of meats, fowl, and sea foods. All of the available procedures typically involve the grinding or crushing of meat followed by chemical and physical extraction with hot water, steam, heat, pressure, or some combination of these treatments. One of the primary challenges remaining is the appreciable removal of cholesterol and total fats located in inaccessible components of the meat. Virtually all of the cholesterol in edible meats exists in the free form and is located in the membranes of the cell within the meat tissue rather than in the meat (muscle) itself. On the other hand, most of the fat exists in the adipose tissues wherein the fat is embedded in connective tissues. Intramuscular fat represents a good portion of marbling and is the most difficult to eliminate. However, neither cholesterol, fat nor saturated fat can be effectively extracted from edible meats and meat products simply by employing heat, water, or steam. Water and steam can be employed to melt some fats, which then can be physically removed in part. Nevertheless, these treatments cannot substantially extract the cholesterol or fat and saturated fats of meat, particularly in the case of red meats such as beef, pork and lamb.
The need for a commercial process for adding value to the less demanded high fat meats and low value fish has always been desired as well. In addition to the nutritional attributes of such low-fat products, the organoleptic properties of the finished products could be greatly improved resulting in a significant profit for the industry.
It is therefore an object of the invention to provide an improved natural method for producing a low-fat meat product.
It is another object of the invention to provide a novel method for producing a low-fat red meat, fowl or fish product.
It is a further object of the invention to provide an improved meat product having low-fat content and low-cholesterol content.
It is yet another object of the invention to provide an improved low-fat meat product and method of manufacture producing a meat product having intramuscular and connective tissue fat and intracellular cholesterol removed.
It is still a further object of the invention to provide a novel method of producing high quality meat products from low quality starting meat products.
Other objects and features of the invention will be set forth in the detailed description, examples and claims and in the drawings described below: